lance's d'huez wheels

Discuss light weight issues concerning road bikes & parts.
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520 Dan
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by 520 Dan

in the states, if you watched tour coverage on OLN, Frankie Andreau had lance's bike and was talking about the Bontrager wheels. He said older versions were 110 OCLV, but lance had a new 55 OCLV rim on his wheels. Andreau then stated that the wheels weighed right around 1000gm. What I'm wondering is, if theoretically the new rim weighed half as much as the old rim (or even 2/3) and there are new hubs that are quite a bit lighter, and the old wheels weighed about 1200gm, why isn't the weight a lot closer to 900gm? Do you think that Andreau was just guessing?

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Xterra Racer
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by Xterra Racer

From what I have heard when listening to Frankie on OLN is that he tends to exagerate a bit. I think he talks with in this manner to try to make it more dramatic for the average viewer on OLN.

He did the same kind of thing a few days ago when he was talking about the OCLV55 frame that Lance used today. He just likes to talk things up.

wanderingwheel
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by wanderingwheel

Go to Bontrager's website to find out more information about the new wheels. Supposedly the new 55gsm rims weigh 205 grams.
http://bontrager.com/tdf/

When using 55gsm carbon rather than 110, the weight of the part does not go down by a factor of 2. It is a function of the amount of carbon needed in order to have sufficient strength. Using 55gsm carbon allows the designers to build with less excess material. For instance, if a part had two layers of 110 carbon they could possibly go to one layer of 110 and one layer of 55, reducing the weight of the carbon by 25%. The total part weight change would be probably be slighlty less because the amount of resin used is similar.

Sean

520 Dan
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by 520 Dan

good to know,but that still doesn't answer why those wheels aren't lighter.

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Xterra Racer
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by Xterra Racer

All goes back to the fact Frankie doesn't really know what he is blabering about.

520 Dan
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by 520 Dan

thats kinda what i figured, but since some people here are experts w/ inside knowledge, i thought maybe someone knew the exact weight.

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Xterra Racer
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by Xterra Racer

Well let's figure it out:

Front Rim weight: 205
Back Rim weight: 205
Front Hub: 79
Rear Hub: 216

total weight (minus nipples and spokes) 705g

Now here is where it get's tricky....they don't list the type of spokes or nipples. So I'll assume Sapim CX-Ray as they are one of the lightest and their aliminum nipples. The weight of a CX-Ray (based on the listings on this forum) are 4.1g each and nipple weight (again based on listings in this forum) are 0.29g each.

From the picture on the Bontrager Web Site it looks the front is 20 spokes and the rear is 24. So a total of 44 spokes and nipples for a combined weight of 193g.

So a conservative estimate of the total wheel weight would be 898g. The only thing I left out was wether the Bontrager claim of 205 include a rim strip. If not, then add 20 grams or so.

So yes, Frankie doesn't know what he is talking about :)

MiNtzNUrMth
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by MiNtzNUrMth

2Xrims = 410
front hub=79
rear hub=216
20 sapim spokes=87
26sapim spokes=113
total= 905

Thats just guessing he would use sapims. I would hope he would but you never know. If all the weights they claim are correct that would be a sweet wheelset.

MiNtzNUrMth
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by MiNtzNUrMth

sorry Xterra Racer :oops: we were thinking the same thing but i thought i counted 26 maybe im retarded though. :cry:

MiNtzNUrMth
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by MiNtzNUrMth

why would they include a rimstrip in a tubular wheel weight?

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Xterra Racer
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by Xterra Racer

I counted 24 on the back....checked it twice.

Your right on the rims strip thing....I was thinking clinchers for some reason....of course they would be tubies.

C-40
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by C-40

Would (should) his wheels have been labeled "uphill only"?

There was some talk on "the Chronicles According to Lance" that the 55gm/m2 bike was questionable in high speed decents...... should they have labeled his bike "uphill only" also?????

rom
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by rom

Most of the talk of the 55 gsm material is marketing BS. Yes it is satellite material but so is every other unidirectional prepreg. The 55 gsm refers to the material fiber weight in grams per square meter. The implication that it is somehow special is not true, you can order prepreg material in a wide range of areal weights. There is one advantage of a low areal weight, more flexibility in fiber placement. If you use 2 plies of 55 gsm material you can position them so they each lie in a different orientation vs one ply of 110 gsm material which can only have the fibers in one direction. This allows you to have a more intricate (optimised) layup for the same part thickness. But, a rim is an extremely simple structurally, which doesn't need complex fiber placement to resist the loads, but a lug for a bike joint may benefit from the added flexibilty in fiber placement. Also the OCLV acronym is redundant. Why would anyone sell a composite part that had any less than optimum compaction and low voids?

Sorry for the long post. I guess my point is to be a informed consumer and do not believe engineering done by the marketing department.

ShinyBaldy
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by ShinyBaldy

rom wrote:Most of the talk of the 55 gsm material is marketing BS. Yes it is satellite material but so is every other unidirectional prepreg. The 55 gsm refers to the material fiber weight in grams per square meter. The implication that it is somehow special is not true, you can order prepreg material in a wide range of areal weights. There is one advantage of a low areal weight, more flexibility in fiber placement. If you use 2 plies of 55 gsm material you can position them so they each lie in a different orientation vs one ply of 110 gsm material which can only have the fibers in one direction. This allows you to have a more intricate (optimised) layup for the same part thickness. But, a rim is an extremely simple structurally, which doesn't need complex fiber placement to resist the loads, but a lug for a bike joint may benefit from the added flexibilty in fiber placement. Also the OCLV acronym is redundant. Why would anyone sell a composite part that had any less than optimum compaction and low voids?

Sorry for the long post. I guess my point is to be a informed consumer and do not believe engineering done by the marketing department.


;) you might get lynched by some LA/Trek zealots for saying that publicly in the US :lol: :lol: :lol: *rides a 5200 here but could care less if it is 110 or 120 OCLV*

ps ;) haven't you heard? Those mono, non-lugged composite frames are unoptimal compaction high void bikes :P surely the human hand pushing against the mold provides more pressure and consistency than a pressurized internal bladder pushing out against a mold ;)

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